Inheritor
by benignmilitancy
Summary: On Sonic's birthday, Eggman has a package posthumously delivered to him. It contains a card: 'Catch me if you can,' with a single brass key. No one knows what the key unlocks—except Shadow. One-shot.


_A/N: Honestly, I don't really have an excuse for publishing this other than the fact that I started this back in 2016 and abandoned it for a few years until the premise caught my eye again. With that in mind, I probably had a different set of goals in mind when I began writing it. _

_Some old notes on this fic mentioned that I intentionally was steering this toward an icier characterization for Eggman. So that's pertinent to know going in._

* * *

_Inheritor_

* * *

The Doctor is dying. He's been dying for some time now, and faces the wall of the cell with the surety of one who has resigned himself to waiting. His hands remain unusually still over the battered tabletop as he stares at the concrete directly across from him.

GUN's insignia lies painted in stark reds and blues, twin circles orbited by seven white stars. As it flickers in and out of focus due to the bulb's sputtering beam, he regards it as though nothing exists there. Eventually a roach scuttles across its surface, dappling the smoky light of the lone sconce.

He sniffs.

The sheer calm he exhibits in the face of his circumstances no longer surprises Shadow, but it does raise some concerns. Even at his most silent, mulish and fuming, he has never been this docile. Never. It brings to the hedgehog's mind the image of a wounded predator as it gleams bright, hateful eyes in the dark.

Although he cannot read hatred or any other emotion behind the thick sheen of glass separating him from the Doctor, something hazardous resides in the Doctor's withering body that even he cannot deny. He's hesitant to call it the soul's last warning, but there is a danger deeper than the quickened blood in his veins and beyond what any mere sight can tell him.

Just as Shadow reaches out to touch the warmed glass, he jerks back from the shock of a voice speaking to him.

"C'mon, now. They just washed that." One smooth upwards roll of her shoulder tells him just how much concern she gives the matter. "Just lookin' out for your best interests, handsome. Don't come crying to me if custodial strangles it out of you."

After taking a moment to listen to the fluorescents hum, he folds his arms. "This is barbaric."

"Maybe." Rouge has never flounced her words even when the situation warrants it.

"_Shadow." _He tips his head but gives no verbal affirmation to the guard who addresses him. _"He wants to see you."_

He and Rouge silently study the other before the admittance buzzer shrieks.

Her eyes glitter darkly as she narrows them—a deep resistant spark, and her painted mouth tucks thin at one corner. But despite whatever misgivings she holds, she abandons them to let him aside. She knows well enough when making a wish for luck is futile.

"Doctor."

His greeting is always the same. Whether he deserves the respect attached to his title is another question entirely, and not one Shadow is always equipped to answer.

Shadow stands beside the table, beside the Doctor, waiting for him to speak in the bright coldness of the interrogation cell. It's brighter here than in any other room for sake of making suspects uncomfortable, both color and chill nearly at a painful saturation. He can hear the concrete crackle as well. A host of minutiae become more salient the longer the silence between them grows.

He tries again. "Can you hear me?"

"In surround sound," the Doctor pries his hands apart with pronounced stiffness cracking his finger joints, one by one, "because I'm _blind,_ you fool, not deaf. Now come over here so I know where you are. Yes, _now._ I hate speaking to people from the side."

There is a long pause. Then—he beckons Shadow in a gesture so reminiscent of the Professor that he feels displaced for a brief moment.

"For Pete's sake," he hoarses, "come _here._ I'm not going to bite you." Shadow stops a foot short of the table. "You must be wondering why I had them call you in here. To be honest, I was wondering the same thing. But then I remembered."

As if to tell Shadow that his failing body obeys no other whim, he bends aside to suffer another short but violent coughing fit. These days his jags rarely cease, and give him less peace of mind than anything else he has.

"Considering who wants this information, I wouldn't have even bothered." He wipes his mouth with the back of his wrist, hairless brows furrowing slightly together at the spittle he gleans from the gesture. Grimacing, he flicks his fingers away from himself, scrubbing his knuckles hastily against the fabric of his sleeve.

Shadow asks the obvious. "Why now?"

The Doctor looks in his direction. And then he laughs, for the first time in months, in a somewhat hoarser imitation of its former self. "Don't you have eyes in your head, boy? Look at me! I mean really _look._ How much longer do you think—"

Shadow's jaw cracks as he pries it open. "I assure you, I insinuated nothing of the—"

Through teeth clenched together in a painful smile, he gruffs: "Bite me, you overgrown lab rat."

* * *

Sonic has questions for him on a chilly day in September. His bright blue crackles against the fiery plumage of swaying leaves.

He kicks his heel at the concrete. "What'd he have?"

"Maria's disease," Shadow replies. "He was a carrier."

A leaf scuttles by, making him draw his brows together. "But... " He grips the worn bench edge. "That doesn't make sense. Aren't carriers immune to whatever they got?"

"Normally, yes. This was an inherited ailment, so he couldn't fight it the same as a bacteria or even a virus. He was asymptomatic as well. By the time he'd realized it, it was already too late."

Sonic goes silent again. He rises, though not against expectation, and wanders around the block at a brisk pace, his circuitous thoughts inevitably dragging him back to the bench.

Shadow doesn't ask if he has any more questions. He wouldn't be so cruel as to prod. But Sonic huddles, hunches his shoulders against the impending cold, not enough to bite, just snapping. There is a slight shiver in the tips of his ears.

"You should've brought a scarf."

"Yeah?" He plucks a leaf that flutters into his lap and holds its brittle, veiny flesh to the pale autumn light, turning it this way and that.

"You wouldn't be shaking right now."

A crisp wind gusts through, tearing the leaf from his grasp. He regards its absence with a wan smirk. "Guess I just keep thinking summer ain't over."

* * *

"GUN's begun work dismantling his old bases," Shadow begins.

"Lemme guess," Sonic says. "They want me to help."

"_Want _may be too strong of a word." Red eyes gaze unflinchingly into green. "But yes. There are certain weapons which require cautious—decommission."

"Hedgehog in a coal mine, huh? You send me down and I tell you everything's all clear, right?"

"Essentially."

"C'mon, Shad," he says with a deep sigh, "if these guys really wanna nuke his stuff, there's nobody stoppin' them. Door's wide open."

"Then why won't you step through it?"

As usual, Sonic has no answer.

* * *

Rouge has long since stopped asking him the question, but there are times it rekindles in her like a light that refuses to die. Curiosity will emerge in her carefully composed mien, the silent gemlike glitter that skims her turquoise irises betraying her mind and, more importantly, the calculation going on within it.

Either way—it's tiresome, this business of pretending not to know. He can't say how she manages it on a daily basis, deceiving others as part of her job description, but he has to admit she does it better than most. It's just a shame that he can't allow himself to be fooled so easily, even if he were to somehow aid her and the rest of GUN in this mass delusion. His mind, already roiling, would tear him to shreds.

" ...Hey. Prince Charming."

He looks up to find her standing akimbo in the doorway.

"I can't say I get what you're trying to do, but... be careful."

* * *

_"Run, Shadow!"_

He does, till his legs burn. His shoes skid liquidized flames over singed wooden floors, cinders snapping fangs at his back. Shadow quickens his pace as he hears a madman's laughter echo down the hall, in a raucous shout that could wake the dead.

_"Ladies and gentlemen, good evening all! I hope you haven't forgotten about me_—_but no matter if you have, since I guarantee you won't be able to forget!"_

* * *

The Doctor coughs. "Why'd you have to drag _him _in here?"

"Good morning, Doctor," Shadow says, the coldness in his voice belying its obvious politesse. Ruby eyes flickering over his body, he adds, "You appear well."

"What are you, my mother?"

The swarthy patches flaring under the Commander's nostrils turn a hazardous shade of red. However, Shadow continues undaunted. He turns to the Commander and produces a small plastic bottle bearing an unprinted yellow label on its face.

Empty, of course. But test trials usually are.

"Robotnik," the Commander begins, his voice a bit louder than it should be.

He returns its blunt, recalcitrant tone. "Abraham."

Rigid fury inflames the Commander's eyes. Shrunken pupils ebb inside the wells of two different colors. Cyan and amber.

A fat portfolio slaps the table before the Doctor, raising plumes of dust under its weight.

"You're not eating." The Commander stands sharply up. "You're not sleeping." And the Doctor turns, nose raised in the air. "If you want to die in your own place and on your own time, then personally that's just swell with me. Have a party, invite your imaginary friends. Make it a grand affair. But you're not offing yourself while you're being held under _my_ jurisdiction, do you understand?"

A slow grin overtakes him. It's here that he must play his part. Make it grand.

"Why, Commander," he says, his voice slightly gravelly with an unreleased cough. "I'm touched. Truthfully I didn't know I meant so much to you people. But that's to be expected, as, after all, I'm practically one of the family now."

"None of the medications are working, Commander." Shadow's interruption earns him a pointed glare. "They say they're going to have to resort to more aggressive measures if this one doesn't at least slow the degeneration."

Eggman wipes the sweat from his brow, grimaces at the damp mottle on his palm. "More _'aggressive'_ than turning my kidneys into punching bags? I doubt it."

"Enough," says the Commander. "You'd better not die before we can settle this issue. It's more than you deserve."

* * *

GUN fought itself in a hot, windowless room for weeks.

As time went on, the room divided itself into two camps: those who advocated punishment, whatever it entailed, and those who felt keeping him alive would yield them a greater benefit in spite of his crimes.

Strangely enough, no one mentioned Sonic.

"This isn't the dark ages, for heaven's sake," yelled the practitioner as he flapped a soggy manilla folder over himself. "Forget what protocol demands for a moment. We have to consider the intrinsic value of the life in question_—_"

He was soon devoured by a tidal wave of shouts and reprimands.

"He's a _murderer, _plain as day!"

* * *

A rustle sounds as his opponent folds his arms. "Well?" the Doctor asks. "Hurry up. I'm not growing any younger here."

Shadow picks up the queen.

The Doctor snorts. "No."

Sets it down and chooses the pawn instead—

"Wrong."

The bishop, then—

"Are you _trying _to throw the game?"

"Forgive me, Doctor. It's... been quite some time since I've played."

* * *

_Hello, Shadow. Surprised to hear from me? I'll bet not. I think you and I both know I'd rather eat this key than let Sonic have it. Ah, well. Can't fault a man for wanting to have a little fun, can you? _

_The hour before he died, my grandfather suffered an inconvenient little phenomenon he called "a startling moment of clarity." Can't blame him; trips the best of us from time to time. _

_You or I would recognize it as too little too late. Chickens coming home to roost, whichever cliche suits you most. Whatever we choose to call it doesn't matter. Because of it, he felt compelled to record the moment as his last diary entry. _

_And yes, before you ask. I did read it before turning myself in, as per your suggestions_. (_Wholly unnecessary ones if you ask me, but who are you to listen to me? I'm only the man's blasted grandson, after all. Wasn't as though I'd read it before and used the content to blow the stinking manhole cover off your government's lies or anything._)

_I've read it so many times now I could soliloquoy his last breaths. Might I add my heartfelt thanks for the reminder, by the way, seeing how my memory's not quite the crack of the whip it used to be? You won't believe how often I forget my own grandfather's televised execution—right up there with losing my keys!_

_Oh, don't be such a fuddy-duddy. It was a joke. Stay. You have questions to ask, and I'm the only one who can answer them, so let's get this over with, eh? You go ahead now and make yourself comfortable; I'll be here when you're ready to face facts. And who knows? With any luck, a fleeting moment of wisdom might just fall from the sky and hit you too._

_Well. _

_That's if you survive my next trick._

* * *

Eggman has a package posthumously slated to be delivered to Sonic on his next birthday. They screen it for possible hazards: explosives, biological contaminants, down to more pedestrian concerns like needles and knives. Results turn up clean, which only grows his suspicions. Shadow is of half a mind to simply dispense of the problem by throwing it away, but the higher-ups override his wish.

The quickest way to extinguish the light from the birthday boy's eyes is to let him open the box. He finds a key inside, a single brass key, with the accompanying card scrawled in a hasty, childish script: '_Catch me if you can, Sonic.' _

_Huh,_ is all Sonic says. _Here, Tails._

Tails believes the key must unlock a door inside one of his bases. Which, and for what purpose... He scratches the back of his head, stumped.

Maybe it unlocks his cold heart, Rouge quips, prompting him to shake his head.

* * *

A pair of bluebirds perch on a twisted hank of metal, basking in the sunshine pouring through the dozer-inflicted gash in the roof. One spots a cockroach that makes a break for it and sweeps low, catching the writhing insect in its beak. Its partner scoffs at not being offered the courtesy of sharing, and they erupt into possessive, squawking chirrups.

Rouge sighs. "Was hoping the wildlife wasn't gonna come back yet. Boys are still picking up after that nasty radiation spill in the lower chambers."

Machinery growls at its thankless work.

* * *

Omega's memory banks have been scoured of all traces of the Doctor's original programming. He maintains that the key is trash, not even worth the scrap metal it'd melt down into.

Chuck it, Sonic says. He's just trying to spook us.

The Commander is more succinct. Some keys don't have doors, Shadow. Simple as that.

* * *

One morning, Eggman gives his company a facetious smile and waves soundlessly through the observation window.

"Docile as a hand grenade," the Commander mutters. "Listen to me, Shadow. I don't want you going in with certain expectations and getting hurt by them."

Shadow recalls with distinct clarity the pain and rage contorted in the Commander's face as the gunshot rang out in the ARK's stale, dust-ridden air. Now that same man who wanted to kill him warns him of the dangers of another man he once entrusted to carry out the Professor's will. One thing's for certain: humanity will forever remain an enigma to him.

"Perhaps he'll only lash out." He glances out the frosty window before continuing. "We'll need to take the risk either way. If he dies, that knowledge dies with him."

There is a brief silence.

"Shadow," the Commander replies, his tone gone softer. "He's spent his entire lifetime talking people in knots. What makes you think you'll fare any better?"

His eyes glitter in the light. "Watch me."

* * *

"Funny," the Doctor says the moment the hydraulic doors slide apart. "I don't remember asking for a priest."

"I know this sickness," Shadow says. "This isn't how it normally manifests itself."

"Oh, so now you think I'm faking it? Faking _these_?" He throws up his shackled hands until the links strain against the cuffs. "I'm _asymptomatic,_ you twit, on top of suffering late onset."

"I wouldn't be so quick to judge, Doctor, seeing how I may not be entirely dispensable to you."

He sniffs. "What are you playing at?"

"My blood resists disease by producing binding antibodies. It can't stop the worsening of those in-progress, but it can retard the effects somewhat." With those words, the Doctor straightens, interested at the prospect; he becomes a cure once again. He stares at the floor, lost in another time. "Truthfully, I don't like having to resort to this, either. But you've left us little choice."

"You fool," the Doctor cries, "you think I've been holding out on you because I _enjoy _it? Hah! Close, but no cigar." His appeasing smile invites danger. "Try and see it from my point of view. If I act like a good boy for once and give you the information you need, who's to say you won't turn around and cast me aside like yesterday's trash?"

"I won't let that happen—"

"That's not _good _enough," he says. "Promise me." And he says this so softly it nearly passes undetected through Shadow's eardrums: "Swear it. On her life."

The wicked will invoke anyone if they believe it will save them. The Commander has warned Shadow he'd dredge up the past.

"No."

"I wouldn't ask you, Shadow, if I didn't think it that dire."

* * *

"Well?"

"Well what?"

"Feel like a pincushion yet?"

Shadow touches the soft gauze pad taped to his elbow.

"You know, I hear when you give blood you actually become closer to the recipient," Rouge says between sips of coffee. "Or maybe that was an organ. How much do you think your heart'll fetch if he kept it in an ice bucket?"

"Rouge, stop."

"Just teasin' ya. Seems by the look of things, he'd rather chew it up and spit it out, anyway."

* * *

Broken glass shrieks, heralding a symphony of alarms.

_"RUN, RUN, SONIC,"_ Eggman screams between hysterical peals of laughter, _"AS FAST AS YOU CAN, YOU CAN'T CATCH ME I'M A DEAD MAN_—_"_

What happened? The Commander bristles at Shadow's piercing eyes. His mind's a rusty hinge, he says, tense and biting and brittle. It was bound to snap at some point.

"Shut up—" They hear him rail at the emergency responders, hear him throw chairs and fists. "Shut up! SHUT _UP!"_

These days he quarrels with empty air, calling it Gerald.

(_stop talking about her she's gone you hear GONE_)

(_I was not the defect, I WAS NOT THE BROKEN ONE_)

(_NO MATTER WHAT YOU SAY_)

(_I AM NOT THE MISTAKE_)

* * *

Checkmate. The Doctor sweeps the pieces into his massive, shackled hands. "Go ahead and say it."

"Say what?"

"That you don't think it's fair, me being here in her place." He points to their respective IVs, one ingoing, one outgoing. A one-sided symbiosis. "It's killing you, what my grandfather intended you to be versus what you're actually being used for. Just twists the proverbial knife in your wounded little heart."

"It's blood," Shadow says. "Nothing more."

"Oh, I wouldn't be so quick to dismiss it. Blood is the only thing you and I have, after all, aside from a name. One you don't even use."

"Neither do you."

"My point exactly. It's what we discard that makes us what we are."

"For what it's worth, Doctor, I don't believe it's fair. But that isn't how the world works. If we all got what we deserved... "

He grins, as if to say, I dare you to finish that sentence.

"You don't have regrets?" Shadow asks him. Out of curiosity, nothing else.

"Not a one."

"Why?"

"Why not? I've given it my best shot. No use crying over the outcome."

"Your overseeing practitioner says there is a slight chance your condition could improve."

"And wouldn't that be just peachy for you and everyone else? Yes, and maybe rainbows will shoot out of my eyes, hedgehogs will sprout wings, and fairies will grant children their every candy-coated wish."

Shadow tries honesty. "Some of the staff claimed you were getting what you deserved," he says, adding: "I disagreed."

"Wonderful. Go bleed your heart out somewhere else."

She couldn't feel pain, not toward the end. There were days Maria couldn't get out of bed unless she received his blood. What would normally be a mercy instead became a sign she was beginning to slip away, and so did the rest of them, becoming ghosts at the fading of the light.

"I will provide you life as long as you need it," Shadow says. "But you must realize there is also a time to let go. When you decide to do so, I will be there to accompany you."

The researchers would ask themselves: Why did evil flourish while good withered? He now knows the decay remains the same for both; it just chooses a different path.

"You're a selfish creature, Doctor," he continues, "petty and apathetic. But... "

"Shadow." There is no possible way he can finish this thought, and the Professor's grandson knows this well. "I am not my cousin."

* * *

Sonic asks questions he can't answer.

"I mean, we're all free now, right? So why does it feel like... "

"Something important has come to an end?" Shadow finishes. Sonic dips his gaze toward the ground. "I don't know."

There is a certain thought hovering in his mind, a perilous one. "I doubt," he says, "the Doctor was capable of love outside the love he had for himself. But he said something that made me believe, if just for a moment, in some perverse way... " Leaves rain and patter, whispering on concrete. "It's as if... he felt his schemes had helped raise you."

Sonic's eyes flicker fire. "No."

"Not willingly," he says. "Not consciously."

"No, Shad, just— _Stop."_ Sonic hardens, his defenses raised along with his outward-facing palms. "Whatever it is you're gonna say, don't, okay? I don't want to hear it. He's gone. That's—all there is to it."

A sonic boom steals the leaves off the knobby branches as well as his next words, leaving him sitting alone on the bench. And he feels that the wisest thing Sonic could have done. Shadow may not like his rival's lackadaisacal approach to most things, but he can't fault his staunch philosophy of never turning back.

* * *

"I used to envy you," the Doctor tells him between moves, "your ability to live without time affecting you one bit." The pieces click. "A century," he says. "Think about it. Composed of days and weeks, each hour a century of its own. At a subatomic level, each second spans an infinitely smaller and smaller set."

He's cornered Shadow, so all he can do now is watch his forces fall, one by one.

"I know what will happen to me in a hundred years' time." Jumping bishops, advancing on the king, no escape. "My bases will rust. My fleets and fortresses will crumble or be destroyed in one of your junkyards because none of you will know what to do with them. Everything will rot and stink, possibly contaminate land and water and threaten wildlife as well. All I'll be, all I'll have struggled to become—stains."

He knocks down Shadow's king so hard it rolls into the cell's farthest corner. Claims another ultimately meaningless victory.

"But you, you're destined to remember what I've done. Destined, designed, or cursed, depending on how you want to look at it. So I probably shouldn't fear the big sleep the way I do, eh, knowing I'm firmly entrenched up in there?"

"My memory is not that reliable, Doctor."

"Better than Sonic's, at least." After a moment of reflection, he mechanically sweeps the board clean for another reset. "_Hmph._ I'll bet he won't have much to worry about anymore."

Shadow's ears prick a little. This is the first time he's mentioned Sonic by name, much less speculated how his foe will react to the news.

... Can he take it as a sign of progress? He'd like to think so, but his more rational side warns him this may just be a simple bloodletting, allowing the poison to flow unfettered.

The Doctor taps his fingers against the tabletop. "It bothers me."

"What does?"

"You don't pay much attention, do you? I want it to mean something, Shadow. I want it to mean something to him."

"You want it to hurt him."

"No, I want him to dance a_ jig_. Make it a fabulous production."

"Which part bothers you, exactly?"

He shakes his head ever so minutely. "In a month or so, you'll know for sure whether I've even left a dent in his psyche. But I suppose it won't matter, since I won't be around to see it." This time, he reverses sides: white on Shadow's, black on his. "I want you to tell him something."

"Deliver a message?"

"Of sorts. And don't you dare try to pretty it up, either, or I'll make you wish you hadn't."

"I thought you didn't believe in ghosts."

"Oh, ho, Shadow. How naive of you."

He is silent. A page waiting to be written on.

"Tell him everything belongs to him." Eggman clears his throat, and for once his voice remains strong. "Not the bases, those are mine, but everything else. Every gray hair I developed, every piece of machinery I broke, every thought I strained, every blueprint I tore, every hope I crushed, those are what belongs to him. Tell him he can keep running from them all he likes, but they'll find him one way or another. And when he starts whining, like I know he will, tell him if he's got any spine left, he'll come and take them."

* * *

The key fits in exactly one hole: the door to the Professor's library.

Nothing there, of course, except singed wooden shelves, blackened and empty. As he explores the dark, derelict aisles, he recalls the Doctor telling him of a childhood memory. According to him, a protestor hurled a flashbang through the window, catching valuable research on fire. All that work, wasted.

He never intended for Sonic to wield the brass key into his memories. In fact, he'd counted on Sonic relenting Shadow the key. Sonic was only the means, the pawn that must be knocked out of the way to advance on the king.

Shadow's ears catch a faint, chirping countdown, followed by maniacal laughter.

_"Run, Shadow!"_

Once outside, he watches flames engulf the Robotnik manor, climbing toward the ARK.

* * *

"You're lucky, Sonic."

"How?"

"In time," Shadow says, "you'll forget."


End file.
